Company lists · Data refreshed September 2026

Top 25 Onshore drilling contractors based in the United States

Name: Onshore drilling contractors based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 17, 2026 970 companies tracked

RevenueBase identified 970 onshore drilling contractors headquartered in the United States as of September 2026 and tracks 72,551 professional contacts across them, including 12,986 with verified work emails. Houston is the largest hub.

This list covers onshore drilling contractors headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 17, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 17, 2026 86% judged on-target in blind review

970Companies

72,551Contacts tracked

12,986Verified emails

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The 25 largest onshore drilling contractors based in the United States

Ranked by team size

Top 25 of 970 onshore drilling contractors based in the United States, ranked by team size, largest first. Data refreshed Sep 17, 2026. RevenueBase Smart Search rates how each company's information relates to onshore drilling contractors: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Nabors Industries	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	10001+	5,865 contacts →
	Indirect evidence “Nabors Industries is a leading provider of advanced technology for the energy industry.” Source: RevenueBase Database · checked Sep 17, 2026
2	Noble Corporation	Strong evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	5,001-10,000	5,601 contacts →
	Strong evidence “Noble is a leading offshore drilling contractor for the oil and gas industry.” Source: RevenueBase Database · checked Sep 17, 2026
3	Boart Longyear	Partial evidence	West Valley City, UT, United StatesHQ checked Sep 17, 2026	5,001-10,000	3,285 contacts →
	Partial evidence “Established in 1890, Boart Longyear is the world’s leading innovative provider of drilling services, manufacturer of productivity-driven drilling equipment and performance…” Source: RevenueBase Database · checked Sep 17, 2026
4	Valaris Limited	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	5,001-10,000	3,173 contacts →
	Indirect evidence “We Are Valaris With decades of expertise and strategic commitment built on efficiency, capability and ingenuity, our sights are continually set toward a future built with purpose…” Source: RevenueBase Database · checked Sep 17, 2026
5	KEY Energy Services	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	1,001-5,000	2,755 contacts →
	Indirect evidence “Headquartered in Houston, Texas, Key Energy Services provides a wide array of leading edge energy production solutions and services.” Source: RevenueBase Database · checked Sep 17, 2026
6	Patterson-Uti	Partial evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	10001+	2,317 contacts →
	Partial evidence “Patterson-UTI is a leading provider of drilling and completion services to oil and natural gas exploration and production companies in the United States and other select…” Source: RevenueBase Database · checked Sep 17, 2026
7	OIL States International	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	5,001-10,000	2,215 contacts →
	Indirect evidence “Oil States International, Inc.” Source: RevenueBase Database · checked Sep 17, 2026
8	Superior Energy Services	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	1,001-5,000	1,938 contacts →
	Indirect evidence “For oil & gas exploration and production companies worldwide, Superior Energy Services is an oilfield products and services company with global reach, financial stability and…” Source: RevenueBase Database · checked Sep 17, 2026
9	Halliburton Energy Services	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	10001+	1,379 contacts →
	Indirect evidence “Founded in 1919, Halliburton is one of the world’s largest providers of products and services to the energy industry.” Source: RevenueBase Database · checked Sep 17, 2026
10	Cudd Energy Services	Indirect evidence	The Woodlands, TX, United StatesHQ checked Sep 17, 2026	1,001-5,000	1,285 contacts →
	Indirect evidence “Cudd offers a broad range of technical and specialized oilfield services to companies engaged in the exploration and production of oil and natural gas worldwide.” Source: RevenueBase Database · checked Sep 17, 2026
11	Stewart & Stevenson	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	1,001-5,000	1,135 contacts →
	Indirect evidence “Stewart & Stevenson is a leading designer, manufacturer and provider of specialized equipment and aftermarket parts and service for the oil and gas and other industries that we…” Source: RevenueBase Database · checked Sep 17, 2026
12	Scientific Drilling	Partial evidence	The Woodlands, TX, United StatesHQ checked Sep 17, 2026	1,001-5,000	1,134 contacts →
	Partial evidence “THE ULTIMATE PARTNER IN WELLBORE PLACEMENT Scientific Drilling International is an independent service provider offering a complete high accuracy wellbore placement and drilling…” Source: RevenueBase Database · checked Sep 17, 2026
13	KLX Energy Services	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	1,001-5,000	857 contacts →
	Indirect evidence “KLX Energy Services provides more than 100 mission-critical oilfield services, tools, technologies and equipment to some of the industry’s leading operators.” Source: RevenueBase Database · checked Sep 17, 2026
14	Nine Energy Service	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	1,001-5,000	712 contacts →
	Indirect evidence “With a culture built on high performance and flawless execution, Nine Energy Service is a unique kind of oilfield services company, offering industry-shaping completion solutions…” Source: RevenueBase Database · checked Sep 17, 2026
15	Atwood Oceanics	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	501-1,000	639 contacts →
	Indirect evidence “Atwood Oceanics, Inc.” Source: RevenueBase Database · checked Sep 17, 2026
16	Pacific Drilling	Partial evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	501-1,000	538 contacts →
	Partial evidence “On April 15, 2021, Noble Corporation plc completed its acquisition of Pacific Drilling Company LLC.” Source: RevenueBase Database · checked Sep 17, 2026
17	Ranger Energy Services, LLC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	1,001-5,000	501 contacts →
	Indirect evidence “Ranger is one of the largest providers of high specification mobile rig well services, cased hole wireline services, and ancillary services in the U.S.” Source: RevenueBase Database · checked Sep 17, 2026
18	Cactus Drilling CO	Strong evidence	Oklahoma City, OK, United StatesHQ checked Sep 17, 2026	1,001-5,000	440 contacts →
	Strong evidence “As the largest privately-held domestic land drilling contractor in the United States, Cactus provides competent, motivated personnel utilizing premium equipment to meet and exceed…” Source: RevenueBase Database · checked Sep 17, 2026
19	Thru Tubing Solutions	Indirect evidence	Newcastle, OK, United StatesHQ checked Sep 17, 2026	501-1,000	428 contacts →
	Indirect evidence “Only Thru Tubing Solutions offers the specialized downhole equipment and services to deliver the results you need, right when you need them.” Source: RevenueBase Database · checked Sep 17, 2026
20	Express Energy Services	Indirect evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	501-1,000	379 contacts →
	Indirect evidence “Express Energy Services, a leading oilfield services company, is active in every major hydrocarbon basin in the United States and is a premier provider of products and services…” Source: RevenueBase Database · checked Sep 17, 2026
21	AIR Drilling Associates	Partial evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	201-500	328 contacts →
	Partial evidence “ADA is a global energy services company specializing in advanced drilling solutions for oil, gas, and geothermal applications.” Source: RevenueBase Database · checked Sep 17, 2026
22	Total Directional Services, LLC	Indirect evidence	Windsor, CO, United StatesHQ checked Sep 17, 2026	51-200	313 contacts →
	Indirect evidence “Total Directional Services, LLC is a privately owned, managed and operated service company headquartered in Windsor, CO.” Source: RevenueBase Database · checked Sep 17, 2026
23	Nabors Drilling USA	Partial evidence	Pocola, OK, United StatesHQ checked Sep 17, 2026	201-500	295 contacts →
	Partial evidence “NABORS DRILLING USA is an oil & energy company based out of 1803 N GRAY ST, POCOLA, Oklahoma, United States.” Source: RevenueBase Database · checked Sep 17, 2026
24	Leam Drilling Services	Partial evidence	New Iberia, LA, United StatesHQ checked Sep 17, 2026	501-1,000	291 contacts →
	Partial evidence “LEAM Drilling Systems, Inc.” Source: RevenueBase Database · checked Sep 17, 2026
25	Independence Contract Drilling	Partial evidence	Houston, TX, United StatesHQ checked Sep 17, 2026	201-500	286 contacts →
	Partial evidence “Corporate Overview Independence Contract Drilling was formed in 2011 as a vertically integrated premium land drilling services provider.” Source: RevenueBase Database · checked Sep 17, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: onshore drilling contractors. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names onshore drilling contractors.
Partial evidence: Its own public description names part of onshore drilling contractors, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name onshore drilling contractors. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 970 onshore drilling contractors based in the United States

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Onshore drilling contractors based in the United States at a glance

As of Sep 17, 2026

17.9%Verified-email coverage

74.8Average contacts per company

11-50Median size (employees)

16.9%Largest-city concentration · Houston

Sep 17, 2026Page data refreshed

Companies by employee count

1-10

264

11-50

338

51-200

225

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 970 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among onshore drilling contractors, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “onshore drilling contractors”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names onshore drilling contractors), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among onshore drilling contractors, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 12,986 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 17, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Onshore drilling contractors by metro

Onshore drilling contractors in Houston164
Onshore drilling contractors in Midland43

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names onshore drilling contractors, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many onshore drilling contractors are there based in the United States?

RevenueBase identified 970 onshore drilling contractors headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Nabors Industries, headquartered in Houston, tops this list with the largest team on record.

Which city has the most onshore drilling contractors?

Houston leads with 164 headquartered companies, followed by Midland (43) and Odessa (21).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 12,986 verified decision-maker contacts tracked across these 970 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 17, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.